Conveyor systems wherein driverless vehicles are propelled by a chain or the like are known. For example, see U.S. Pat. No. 3,103,895. It is known to transfer a load off such a vehicle on the fly, that is without stopping the vehicle. For example, see U.S. Pat. No. 4,005,787. Conveyor systems wherein a driverless vehicle is propelled by a rotating shaft in contact with a drive wheel on the vehicle are known. For example, see U.S. Pat. No. 3,356,040.
At some locations, both types of systems are utilized. The present invention is directed to a solution of the problem of how to interface the two different types of conveyor systems so that vehicles moving along parallel juxtaposed portions of the conveyor systems may be caused to move at the same speed.